The heart functions by generating an electrical signal to initiate physical contractions of various portions of the heart in a specific and timed sequence. This electrical signal is generated by the sinus node in the upper right atrial wall near the base of the heart and is conducted through the upper heart chambers, i.e., the right and left atria, and causes them to contract in a synchronous manner.
These contractions force the blood contained therein into the right and left ventricles or lower heart chambers. The electrical depolarization wave then travels through and around the ventricles, triggering their contraction, which forces the blood throughout the vascular system. The contraction of the right and left ventricles proceeds in an organized fashion which optimizes emptying of the ventricular chambers.
The synchronous electrical depolarization of the atrial and ventricular chambers can be electrically sensed and displayed, and the electrical waveform is characterized by accepted convention as the “PQRST” complex. The PQRST complex includes the P-wave, corresponding to the atrial depolarization wave, the R-wave, corresponding to the ventricular depolarization wave, and the T-wave which represents the re-polarization of the cardiac cells.
Certain diseases and conduction disturbances can interfere with the natural conduction system of the heart leading to bradycardia or tachycardia of a heart chamber. In short, various chambers of the heart may be caused to contract too early or too late with respect the intended sequence. Thus, synchronicity between the contractions of the atrial chambers or of the ventricular chambers is lost and cardiac output suffers due to the timing imbalance.
Various therapies exist to treat these cardiac deficiencies and arrhythmias. The problem heretofore has been that the cardiac condition has only been diagnosed in general. That is, although the problem has been determined to exist, little additional information has been provided. Such additional information would allow for a more targeted approach to therapy, rather than utilizing the same general therapy in all cases. The problem is further complicated by the fact that these conditions may not occur continuously. Thus, a patient being closely monitored in a hospital may not have the symptoms in question during the monitoring period. Therefore, the inability to monitor and gather information about these conditions, whenever they might occur has hindered the development of targeted therapies.
Table 1 lists a patent that discloses a rate-responsive pacemaker. Unfortunately, the system described by the cited reference lacks features for sensing, recording and utilizing the data obtained through biatrio and/or biventricular pacing systems in a manner to diagnose and more fully appreciate the nature of various cardiac conditions.
TABLE 1U.S. Pat. No.InventorsTitle5,330,513Nichols et al.Diagnostic Function Data Storageand Telemetry Out for Rate ResponsiveCardiac Pacemaker
The patent listed in Table 1 above is hereby incorporated by reference herein in its entirety. As those of ordinary skill in the art will appreciate readily upon reading the Summary of the Invention, Detailed Description of the Preferred Embodiments and claims set forth below, the devices and methods disclosed in the patent of Table 1 may be modified advantageously by using the techniques of the present invention.